EP0655768A1 - Dispositif d'affichage d'images avec tube plat - Google Patents

Dispositif d'affichage d'images avec tube plat Download PDF

Info

Publication number
EP0655768A1
EP0655768A1 EP94203348A EP94203348A EP0655768A1 EP 0655768 A1 EP0655768 A1 EP 0655768A1 EP 94203348 A EP94203348 A EP 94203348A EP 94203348 A EP94203348 A EP 94203348A EP 0655768 A1 EP0655768 A1 EP 0655768A1
Authority
EP
European Patent Office
Prior art keywords
selection
electrodes
fine
display device
electron
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP94203348A
Other languages
German (de)
English (en)
Inventor
Siebe Tjerk De Zwart
Nicolaas Lambert
Gerardus Gegorius Petrus Van Gorkom
Petrus Hubertus Franciscus Trompenaars
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics NV, Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Publication of EP0655768A1 publication Critical patent/EP0655768A1/fr
Ceased legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
    • H01J31/15—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen with ray or beam selectively directed to luminescent anode segments
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
    • H01J31/123—Flat display tubes
    • H01J31/125—Flat display tubes provided with control means permitting the electron beam to reach selected parts of the screen, e.g. digital selection
    • H01J31/126—Flat display tubes provided with control means permitting the electron beam to reach selected parts of the screen, e.g. digital selection using line sources

Definitions

  • the invention relates to a picture display device having a flat vacuum envelope which is provided with a transparent face plate with a luminescent screen and with a rear wall, said display device comprising an electron supply section for emitting electron currents, and an active selection electrode section having first, preselection, electrodes and second, fine-selection, electrodes, located closer to the screen, for directing a plurality of electron currents towards desired positions on the luminescent screen.
  • the display device described above may be of the flat-panel type, as disclosed in EP-A-464 937, or of another flat-panel type in which electron currents parallel to a display screen are emitted and deflected towards predetermined positions on the display screen.
  • Display devices of the flat-panel type are devices having a transparent face plate and, arranged at a small distance therefrom, a rear plate, in which the inner surface of the face plate is provided with a (for example, hexagonal) pattern of phosphor dots. If (video information-controlled) electrons impinge upon the luminescent screen, a visual image is formed which is visible vi a the front side of the face plate.
  • the face plate may be flat or, if desired, curved (for example, spherical or cylindrical).
  • the display device disclosed in EP-A-464 937 comprises a plurality of juxtaposed sources for emitting electrons, local electron propagation means cooperating with the sources and each having walls of a high-ohmic, electrically substantially insulating material having a secondary emission coefficient suitable for propagating emitted electrons along the wall, and an addressing means comprising an active selection electrode section having (first) electrodes (preselection electrodes) which can be driven row by row so as to extract electrons from the propagation means at predetermined extraction locations facing the luminescent screen, further means being provided for directing extracted electrons towards pixels of the luminescent screen for producing a picture composed of pixels.
  • an embodiment of a display device is characterized in that the fine-selection electrodes comprise n groups of m electrodes each, and in that corresponding electrodes of at least 2 groups are coupled to each other in a series or parallel arrangement for supplying a selection voltage.
  • This mode of arrangement may particularly be implemented in such a way that all fine-selection electrodes and their connections are coplanar.
  • the invention is particularly suitable for use in a picture display device in which electron currents are emitted in propagation ducts of dielectric material (referred to as insulating electron duct display).
  • an embodiment of a picture display device is characterized in that the preselection electrodes of the display unit define extraction locations which communicate row by row with electron propagation ducts, and in that the fine-selection electrodes are arranged on a fine-selection plate provided with fine-selection apertures, each aperture being associated with a pixel on the luminescent screen and each extraction location being associated with at least two fine-selection apertures.
  • an embodiment of a picture display device is characterized in that the number of drive voltages to be supplied by a fine-selection drive circuit corresponds to the number of fine-selection electrodes in a group in which each first fine-selection electrode of a group is coupled to each first fine-selection electrode of the other groups and in which, similarly, each subsequent (second, third, etc.) fine-selection electrode is coupled to each corresponding subsequent (second, third, etc.) fine-selection electrode of the other groups.
  • a picture display device is characterized in that an auxiliary (or dummy) electrode for capturing unwanted electrons is arranged between each extraction location and the associated fine-selection apertures.
  • an embodiment of a picture display device is characterized in that a plurality of groups of fine-selection electrodes jointly constitute a section and in that the fine-selection electrodes are distributed across a plurality of sections, each fine-selection electrode of a section being sequentially selected by means of a drive circuit, each first fine-selection electrode of a section being coupled to each first fine-selection electrode of the other sections and each subsequent fine-selection electrode of a section being coupled to the corresponding subsequent fine-selection electrode of the other sections, the dummy electrodes of one or more sections being coupled to each other and, in operation, being fed with the desired voltage(s) from a dummy drive circuit.
  • Figs. 1 and 2B show a flat-panel display unit 1 of a picture display device according to the invention having a display panel (window) 3 and a rear wall 4 located opposite said panel.
  • a luminescent screen 7 having a repetitive pattern (rows or dots) of, for example triplets of red (R), green (G) and blue (B) luminescing phosphor elements is arranged on the inner surface of window 3.
  • the luminescent screen 7 is either arranged on a transparent, electrically conducting layer (for example, ITO), or provided with an electrically conducting layer (for example, A1 backing).
  • the (dot-shaped) phosphor elements of each triplet are arranged, for example in accordance with a delta arrangement rotated through 90°.
  • An electron source arrangement 5 for example a line cathode which by means of drive electrodes provides a large number of electron emitters (for example, 600) or a similar number of separate emitters, is arranged proximate to a connection plate 2 which interconnects display panel 3 and rear wall 4.
  • Each of these emitters is to provide a relatively small current so that many types of cathodes (cold or hot cathodes) are suitable as emitters.
  • the emitters may be arranged separately or, if combined to one line cathode, they may be arranged jointly. They may have a constant or controllable emission.
  • the electron source arrangement 5 is arranged opposite entrance apertures of a row of electron propagation ducts extending substantially parallel to the screen, which ducts are constituted by compartments 6, 6', 6'', ... etc ., in this case one compartment for each electron source.
  • These compartments have cavities 11, 11', 11'', ... defined by the rear wall 4 and partitions 12, 12', 12'', ...
  • At least one wall (preferably the rear wall) of each compartment comprises a material which has a high electrical resistance which is suitable for the purpose of the invention in the longitudinal direction of the compartments (for example, ceramic material, glass, synthetic material - coated or uncoated-) and a secondary emission coefficient ⁇ > 1 over a given range of primary electron energies.
  • the electrical resistance of the wall material has such a value in the propagation or transport direction that a minimum possible total amount of current (preferably less than, for example 10 mA) will flow in the walls at a field strength in the axial direction in the compartments of the order of one hundred to several hundred volts per cm required for the electron transport.
  • a voltage V generating the field strength required for the transport is applied between an upper electrode 200 and a lower electrode 201 of the rear wall 4.
  • Figs. 2A and 2B show the principle of multi-stage selection.
  • Multi-stage selection is herein understood to mean that the selection from the compartments 6, 6', 6'', ... to the luminescent screen 7 is realised in at least two stages: a first (coarse) stage for selecting, for example pixels and a second (fine) stage for selecting, for example colour pixels.
  • a first (coarse) stage for selecting, for example pixels
  • a second (fine) stage for selecting, for example colour pixels.
  • an active selection electrode system 100 which comprises an (active) preselection plate 10a, a spacer plate 10b and an (active) fine-selection plate 10c.
  • Fig. 2B shows in a diagrammatical cross-section a part of the display device of Fig. 1 in greater detail, particularly the addressing structure 100 comprising preselection plate 10a with apertures 8, 8', 8'', ... and fine-selection plate 10b with sets of apertures R, G, B.
  • the apertures R, G, B are in alignment. However, they are actually arranged in a configuration corresponding to the phosphor dot pattern (see Fig. 1).
  • an apertured obstruction plate 10b having apertures 108, 108'', ...
  • Communication ducts 104, 105 having a cross-section chosen to fit with the, for example triangular arrangements of phosphor elements to be driven are arranged in the spacer plates 102, 103.
  • the (flu) spacer plate 101 located proximate to the phosphor pattern of the luminescent screen 7 has a very dense pattern of apertures 106 corresponding, in this case, to the phosphor pattern.
  • Electron propagation ducts 6 having transport holes 11,11' are formed between the structure 100 and the rear wall 4.
  • addressable metal preselection electrodes 9, 9', etc . extending from aperture to aperture and surrounding the apertures are arranged in ("horizontal") rows parallel to the long axis of the display screen at, for example the display screen side of plate 10a.
  • the walls of the apertures 8, 8', ... may be metallized.
  • the fine-selection plate 10c is provided with addressable rows of (fine-)selection electrodes for realising fine-selection vi a the apertures R, G, B.
  • the possibility of directly or capacitively interconnecting corresponding rows of fine-selection electrodes is important in this respect.
  • a preselection has already taken place and, in principle, electrons cannot land at the wrong location.
  • the minimum number of groups is normally equal to the number of fine-selection apertures required for each preselection aperture (3 in the relevant case), assuming that it should be possible to address each individual fine-selection aperture.
  • a group represents all interconnected fine-selection electrodes, hence one connection.
  • the drive is effected, for example as follows, but there are also other possibilities.
  • the preselection electrodes are brought to a potential substantially linearly increasing with the distance to the electron source arrangement 5, for example by means of a suitable resistance ladder.
  • One or more picture lines are selected by applying a positive voltage pulse of, for example 250 V to the desired preselection electrodes used for selecting these picture lines.
  • Colour pixels are addressed by applying pulses having an amplitude of, for example 200 V to the fine-selection electrodes.
  • the fine-selection electrodes preferably have such an electrical resistance, or are connected to external resistors in such a way that they safeguard the electronic circuits (controlling the drive) against breakdown from the luminescent screen.
  • the number of drives may be limited if the selection of the electrons from the compartments 11, 11' ... to the luminescent screen 7 is realised by means of a preselection (or “coarse” selection) and a “fine” selection.
  • a coarse selection element is either on or off.
  • the fine-selection block determines which screen pixel will be driven. Since always only one line of coarse selection elements is switched on simultaneously, assuming that one line cathode is used, the fine-selection blocks of different lines can be switched jointly.
  • the preselection may be realised in a single mode for each electron propagation duct or in a multiple mode (more apertures per "row") combined with the multiplexing mode.
  • each preselection electrode may be split up into two preselection sub-electrodes which cooperate with two preselection apertures in each duct. Using six fine-selection electrodes for two preselection apertures, this yields, for example two pixels with three colour pixels each. It will be evident that the choice of another mode of multiplexing (for example three preselection sub-electrodes) or another ratio between preselection electrodes and fine-selection electrodes will modify the numbers in the embodiments to be described hereinafter without changing the essence of the invention.
  • Fig. 3A shows N groups of 6 fine-selection electrodes (fse) 13, 13', 13'', ... each being separately driven by means of buffers (bf) each receiving a given fine-selection voltage (Vfs).
  • N is the number of preselection electrodes.
  • Fig. 3B shows the fine-selection voltages Vfs plotted with respect to time.
  • Each fine-selection voltage consecutively needs a value, in this example for approximately 10 ⁇ sec, for selecting the relevant fine-selection apertures (for example, a voltage of 200 V).
  • the non-selected fine-selection electrode convey the same voltage.
  • six fine-selection electrodes should be consecutively selected in this example. This is diagrammatically shown in Fig. 3B by means of six voltages Vfs which consecutively represent a selection pulse (with respect to time).
  • Figs. 4A and 4B show embodiments in which the fine-selection electrodes 13, 13', 13'', ... are interconnected to corresponding fine-selection electrodes of subsequent groups.
  • the number of drivers is reduced thereby, but this time each driver should supply N*N times more power. It is possible to interconnect these groups because the preselection electrodes determine whether the electrons reach the space accommodating the fine-selection electrodes.
  • the fine-selection drive circuit D2 should only supply six different fine-selection voltages Vfs (a, b, c, d, e, f) to the display unit (in this example). These are the six voltages for the first group of fine-selection electrodes (the first and the last group of fine-selection electrodes are shown).
  • the fine-selection voltages to be presented by the fine-selection drive circuit D2 should now be repetitive pulses having a repetition time of 64 ⁇ sec (in this example). Now, the respective voltages a, b, c, d, e and f should also be offset with respect to time and last approximately 10 ⁇ sec each.
  • each fine-selection electrode interconnects fine-selection apertures associated with three successive coarse selection apertures. If, for example both the coarse and the fine-selection electrodes are numbered 1, 2 etc . from top to bottom, fine-selection electrodes 1 2 3 are associated with 3 for coarse selection electrodes 1, 2 3 4 5, etc .
  • a satisfactory selection sequence will then be, for example: coarse: 1 1 1 2 2 2 3 3 fine: 1 2 3 2 3 4 3 5
  • the fine-selection thus "zigzags" a little.
  • the fine-selection may be regular and the coarse selection may be zigzag; then the signal resembles that in Figs. 3B and 4B but the period of time is typically 3 times longer because the coarse selection is meanwhile still switching.
  • the above-mentioned example is based on a 3 to 1 selection system. For other selection systems (a different number of fine-selection apertures per coarse selection aperture, a different metal pattern or a different drive sequence) this is different again.
  • the pulse sequence thus depends on the details of the apertures and the metallization pattern, and on the chosen dot selection sequence.
  • the choice of the dot selection sequence is a compromise between (unwanted) charge effects, simplicity of the electronic circuits, switching power, etc .
  • the video information on the column drivers of the display should also be suitable for the chosen selection sequence.
  • dummy electrodes 14, 14', 14'', ... for capturing unwanted electrons in the ducts between the preselection and fine-selection can be used, as is shown in Figs. 2A and 2B.
  • each fine-selection electrode is separately driven in Fig. 5 by means of drivers and fine-selection voltages Vfs, using the drive circuit D2.
  • one dummy electrode 14, 14', etc . is used for each selection block of six electrodes (shown in broken lines in Fig. 5). All dummy electrodes are interconnected and driven by means of one driver at a voltage Vd from a dummy electrode drive circuit D3.
  • the dummy electrodes 14, 14', 14'', ... continuously convey such a voltage that the voltage is higher than the voltage at the non-selected fine-selection electrodes and is also lower than the voltage at the selected fine-selection electrode.
  • VdN VdN, respectively, in which the voltage Vd has a value which is higher than that of the voltage at the selected fine-selection electrodes if the preselection electrode of a relevant fine-selection block should not pass electrons and has a lower value than that of the voltage at the selected fine-selection electrode but a higher value than that of the non-selected fine-selection electrodes if the preselection electrode of a relevant fine-selection block should pass electrons. It is thereby achieved that unwanted electrons are captured by the dummy electrodes while the dummy electrode does not have any influence when a relevant fine-selection block is "on". Consequently, 6+N drivers are necessary in this embodiment.
  • Fig. 7 shows an embodiment in which the number of drivers is still further reduced.
  • the dummy electrodes are interconnected per three groups of six fine-selection electrodes.
  • the dummy electrodes may be jointly driven per segment of 18 fine-selection electrodes (three in this example) from the fine-selection drive circuit D2.
  • the number of drivers in this embodiment will be N/3 + 18 (generally the formula is: N/n + 6*n, in which N is the number of preselection electrodes and n is the number of groups together forming a segment, while 6 fine-selection electrodes per preselection electrode have been chosen).
  • the wiring patterns for the fine-selection electrodes can be interconnected in groups in different manners. For manufacturing purposes, it is advantageous when the patterns and the interconnections can be arranged in one plane without any insulated crossings.
  • a solution is a series arrangement by means of a meander pattern.
  • Fig. 8 shows a pattern of intertwined meanders for six groups of six fine-selection electrodes. This pattern is limited in that two tracks of the same group will be juxtaposed in the "inner bend". In a colour display device these two tracks should not be associated with one and the same coarse selection aperture because the colour selection for this aperture would then be lost. Consequently, given fine-selection patterns cannot be implemented with such a meander pattern.
  • An embodiment which is more suitable in this respect is shown in Fig. 9.
  • Fig. 10 shows a meander pattern in which the tracks of one and the same group are separated by at least two other tracks. This is usable for a large number of modifications of fine-selection patterns, but it has the drawback that the number of connections increases because the two "separating tracks" can no longer be interconnected in one and the same plane.
  • the tracks in all meander patterns should have a very good conductance because the track length is very large.
  • Fig. 11 shows a parallel arrangement of corresponding fine-selection electrodes, in which horizontal and vertical tracks intersect each other in an insulated manner.
  • the crossings at which the tracks are to contact each other are denoted by means of a "fat dot".
  • This can be realised by positioning the vertical tracks at the other side of the (insulating) fine-selection plate with the interconnected crossings being provided with through-connections, or by positioning all tracks at one side of the plate and providing the non-interconnected crossings with an insulating intermediate layer, or by realising the through-connections in an additional, separately provided connection strip.
  • the invention thus provides, inter alia arrangements for coupling selection electrodes in which the technology of providing these electrodes is as simple as possible and/or the possible fine-selection electrode patterns are such that the number of required selection drivers can be reduced considerably.
  • FIG. 11 and 12 A modification of Figs. 11 and 12 is shown in Figs. 13 and 14.
  • the number of electrodes coupled to a single connection is unchanged, but by choosing different through-connections, the number of through-connection tracks is smaller at the edge so that less space is lost at the edge of the construction.
  • the construction now provides a simpler possibility of implementing the connections of the dummy electrodes between the fine-selection connections, which saves space.
  • the reasons and advantages as compared with the patterns shown in Figs. 11 and 12 are maintained.
  • FIG. 13 and 14 may be described as 2 blocks of 3 groups in 5 sections; each time 3 through-connection tracks next to each other.
  • the drive signals will have an adapted sequence. This means that Fig. 4B will have an extra level of structure on the time scale of blocks.
  • the dummy electrodes will become more complicated in the optimum contrast case: each section has its own dummy electrode. Figs. 11 and 12 have 5 dummy electrodes. Figs. 13 and 14 have 10 dummy electrodes, but since the two blocks have entirely separated selection signals, the dummy electrodes can be interconnected to 5 connections again.

Landscapes

  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
EP94203348A 1993-11-25 1994-11-17 Dispositif d'affichage d'images avec tube plat Ceased EP0655768A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
BE9301297A BE1007780A3 (nl) 1993-11-25 1993-11-25 Beeldweergeefinrichting met een platte vacuümbuis.
BE9301297 1993-11-25

Publications (1)

Publication Number Publication Date
EP0655768A1 true EP0655768A1 (fr) 1995-05-31

Family

ID=3887577

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94203348A Ceased EP0655768A1 (fr) 1993-11-25 1994-11-17 Dispositif d'affichage d'images avec tube plat

Country Status (4)

Country Link
EP (1) EP0655768A1 (fr)
JP (1) JPH07192662A (fr)
KR (1) KR950015481A (fr)
BE (1) BE1007780A3 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7247894B2 (en) * 2004-04-28 2007-07-24 Taiwan Semiconductor Manufacturing Company, Ltd. Very fine-grain voltage island integrated circuit

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0560434A1 (fr) * 1992-03-12 1993-09-15 Koninklijke Philips Electronics N.V. Dispositif de reproduction d'images du type à panneau plat
WO1993021650A1 (fr) * 1992-04-10 1993-10-28 Silicon Video Corporation Ecran de visualisation plat autoporteur

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0560434A1 (fr) * 1992-03-12 1993-09-15 Koninklijke Philips Electronics N.V. Dispositif de reproduction d'images du type à panneau plat
WO1993021650A1 (fr) * 1992-04-10 1993-10-28 Silicon Video Corporation Ecran de visualisation plat autoporteur

Also Published As

Publication number Publication date
BE1007780A3 (nl) 1995-10-17
KR950015481A (ko) 1995-06-16
JPH07192662A (ja) 1995-07-28

Similar Documents

Publication Publication Date Title
US5801485A (en) Display device
JP3110086B2 (ja) 薄型画像表示装置
JPS5853462B2 (ja) 画像表示装置
US4112332A (en) Matrix-addressed gas-discharge display device for multi-colored data display
EP0334438A2 (fr) Appareil pour la reproduction d'images, plat, à tube à rayons cathodiques
US5489815A (en) Flat-panel type picture display device with electron transport ducts and a double selection structure
US5982086A (en) Flat-panel type picture display device
US5557296A (en) Flat-panel type picture display device with insulating electron-propagation ducts
EP0655768A1 (fr) Dispositif d'affichage d'images avec tube plat
US5966109A (en) Picture display device having a flat vacuum tube
US5625253A (en) Flat-panel type picture display device
US5838288A (en) Color display device having color selection time divisions
JPH0777949A (ja) 画像表示装置及び画像表示装置で使用される選択駆動回路及び集積駆動回路
EP0560434B1 (fr) Dispositif de reproduction d'images du type à panneau plat
EP0550103B1 (fr) Dispositif d'affichage à panneau plat muni de conduits de transport d'électrons et d'une structure de selection double
US5811921A (en) Thin-panel display having resistive spacer plate
EP0574084B1 (fr) Dispositif d'affichage à panneau plat avec gain de propagation d'électrons isolante
US4873472A (en) Flat cathode ray tube display apparatus
JP2588525B2 (ja) カラ−表示装置
US4625148A (en) Gas discharge display device with an auxiliary anode control plate
US5986627A (en) Flat-panel type picture display device with electron propagation ducts
EP0626671A1 (fr) Dispositif de sélection à circuits de commande intégrés pour un dispositif d'affichage plat à faisceaux multiples
WO1995028668A2 (fr) Dispositif d'affichage d'image et attaqueur de selection et circuit d'attaqueur integre utilisables dans ledit dispositif d'affichage d'image
JPS61114666A (ja) 画像表示装置
JPS641994B2 (fr)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT DE FR GB NL

17P Request for examination filed

Effective date: 19951130

17Q First examination report despatched

Effective date: 19961001

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 19990213